Continuing our efforts of modification of proteins with glycosides so as to change their properties, we will be synthesizing a wider variety of cyanomethyl thioglycosides, including some di- and trisaccharides. Also planned are syntheses of thioglycosides having an aldehydo-group at the aglycon terminal, which can form a Schiff's base with an amino group of proteins and thus be reduced with borohydride to form a co-valent linkage. Behavior of the proteins modified with these reagents will be examined in greater detail with respect to their biological behaviors, emphasizing their potential application to enzyme replacement therapy. Improvement on the preparation of the gel substratum suitable for studies of cell adhesion will be continued. A promising approach, mono-addition of 1-thioaldose derivatives to bis-acrylamido compounds under controlled conditions, will be tested. Gel layers containing two or more sugars in different proportions will be prepared for cell adhesion studies.